Hydrogen-based propulsion systems may comprise either a fuel cell or an internal combustion engine, for example. Fuel cell systems generally include a fuel cell stack that produces electrical energy based on a reaction between a hydrogen feed gas and an oxidant feed gas (e.g., pure oxygen or oxygen-containing air). The hydrogen-based feed gas and oxidant feed gas are supplied to the fuel cell stack at appropriate operating conditions (i.e., temperature and pressure) for reacting therein.
Hydrogen-based Internal Combustion Engines (ICE) generally include an engine that produces mechanical energy based on the combustion process of hydrogen. The hydrogen-based feed gas is supplied to the ICE at appropriate operating conditions (i.e., temperature and pressure) for being combusted.
In a typical hydrogen-based propulsion application, two types of conventional hydrogen storage may be considered—compressed hydrogen and liquid hydrogen. The storage of liquid hydrogen requires complex, multi-layer, vacuum super isolated (insulated) tanks due to the low storage temperature of liquid hydrogen (approximately 20 degrees Kelvin or −424 Fahrenheit). Over the operation of the vehicle, however, heat will generally penetrate the storage container, causing the temperature of the liquid hydrogen to rise, resulting in the evaporation of the liquid hydrogen. Currently, this evaporated hydrogen vapor is captured and reacted with air to create water before being exhausted or diluted and thereinafter exhausted. This results in a loss of hydrogen which could be used as a feed gas. Accordingly, a need exists for a system able to recapture this hydrogen feed gas.